This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
Found in Motorola documentation from the 90's, this circuit has a high input impedance. The power...
This circuit from a National Semiconductor manual from the 1980s shows how to use the LM388, a...
This circuit was obtained in a 1977 Radio Handbook. The transistor is from the era and the coils...